hello,
I'm looking for the most linear MOS with 240-500V of Vds, TO220 package.
The best is with a very low 3rd harminic distorsion
Thank you in advance for your advice.
Aiacel
I'm looking for the most linear MOS with 240-500V of Vds, TO220 package.
The best is with a very low 3rd harminic distorsion
Thank you in advance for your advice.
Aiacel
Well, I do not know what you are pursuing,
but you should define better what you mean by linear.
I guess you mean having linear Id <->Vgs characteristics.
I suggest that you give a look to the data sheets, so you will see that they are NEVER linear at all. You have to choose by your circuit (e.g. bias) a zone where such characteristic is linear enough for your application (again I guess you are looking for a "zero NFB stuff"). Even more so, third armonic distortion is fundamentally related to the circuit you choose.
All the above is absolutely general, but applies of course to an audio power amplifier.
but you should define better what you mean by linear.
I guess you mean having linear Id <->Vgs characteristics.
I suggest that you give a look to the data sheets, so you will see that they are NEVER linear at all. You have to choose by your circuit (e.g. bias) a zone where such characteristic is linear enough for your application (again I guess you are looking for a "zero NFB stuff"). Even more so, third armonic distortion is fundamentally related to the circuit you choose.
All the above is absolutely general, but applies of course to an audio power amplifier.
Lateral fets generally follow the 'Square Law' as far as transfer, but I don't think they come in TO-220. Without knowing the application, one can only guess what type of mosfet will suit.🙄
common gate are best driven with current source - then the details of the device gm curve don't have much influence
with current drive it would be output Z nonlinearity that limits - usually low order, small in magnitude for Crss when Vds > ~ 2x Vth
so just choose smallest device, with smallest Crss for the required current
laterals can be good but not many options
what are output specs, I,V, dV?
with current drive it would be output Z nonlinearity that limits - usually low order, small in magnitude for Crss when Vds > ~ 2x Vth
so just choose smallest device, with smallest Crss for the required current
laterals can be good but not many options
what are output specs, I,V, dV?
the old hitachi/renesas laterals in the to-220 package are still "somewhat" available ("somewhat available" means they have not been discontinued but you'll have to dig a bit to find them and unfortunately, they are also not cheap).
part numbers are 2sj76 through 2sj79 and 2sk213 through 2sk216. Data here: Power MOSFETs for General Amplifier | Renesas Electronics America
good luck ...
mlloyd1
part numbers are 2sj76 through 2sj79 and 2sk213 through 2sk216. Data here: Power MOSFETs for General Amplifier | Renesas Electronics America
good luck ...
mlloyd1
my DC specs are I=60mA, Vds=90V. dv/dt >250V/us, i = 40mA
I suppose you suggest to calculate the C=i/(dv/dt)=40/250= 160pF.
Is this right ?
so IRF740 (g=5,8; Ciss=1400pF, Coss=220pF; Crss=27pF) and IRF710 (gfs=0,5; Ciss=200pF; Coss=50pF;Crss=15pf) are almost the same because both of them have Crss<<160pf . Is this right ?
you want the least Crss
low Cds/~oss is good too but current drive fixes it up pretty well at audio - both should be lots smaller than what would cause slew rate limiting
http://www.fairchildsemi.com/ds/FD/FDPF3N50NZ.pdf 2.5 pF Crss typ
still way too big a die for your signal current but not many smaller are packaged for the power dissipation
this may also be helpful if you don't mind adding a couple extra parts for way better performance, can debug the potential RF instability
http://www.essex.ac.uk/csee/research/audio_lab/malcolmspubdocs/J10 Enhanced cascode.pdf
low Cds/~oss is good too but current drive fixes it up pretty well at audio - both should be lots smaller than what would cause slew rate limiting
http://www.fairchildsemi.com/ds/FD/FDPF3N50NZ.pdf 2.5 pF Crss typ
still way too big a die for your signal current but not many smaller are packaged for the power dissipation
this may also be helpful if you don't mind adding a couple extra parts for way better performance, can debug the potential RF instability
http://www.essex.ac.uk/csee/research/audio_lab/malcolmspubdocs/J10 Enhanced cascode.pdf
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